Preheat the oven to 400°F (200°C) or 180°C fan.

In a food processor, pulse together the flour, icing sugar, and cold butter until the mixture resembles fine breadcrumbs.

Add the beaten egg and process until the dough comes together.

Shape the dough into a disc, wrap it, and chill for 15 minutes.

Lightly flour a work surface and roll the pastry to about ⅛-inch (3 mm) thickness.

Cut circles large enough to line eight tartlet tins.

Gently press the pastry into each tin, trimming the edges.

Chill the tart shells for 20 minutes.

Prick the bases with a fork, line with parchment paper, and fill with baking beans or pie weights.

Blind bake for 10 minutes.

Remove the parchment and weights, then bake for another 5 minutes until lightly golden. Cool completely.

Meanwhile, heat the milk and vanilla until just below boiling.

In a bowl, whisk together the sugar, flour, and egg until smooth.

Slowly whisk half of the hot milk into the egg mixture.

Add the remaining milk and whisk well.

Return everything to the saucepan and cook over low heat, whisking constantly until thick and smooth.

Transfer the pastry cream to a bowl, cover the surface with plastic wrap, and chill completely.

Once cold, whisk in the heavy cream until smooth and silky.

Spoon the crème pâtissière evenly into the cooled tart shells.

Refrigerate for 20 minutes to help the filling set.

Heat the raspberry jam with the water until smooth, then strain through a fine sieve.

Arrange the fresh raspberries upright over the pastry cream.

Brush the warm raspberry glaze over the fruit.

Chill the Raspberry Tartlets until ready to serve.